As a conventional technology, a current sensor device is known that includes a magnetic core configured to have a ring-like shape with voids and focus magnetic flux generated by a current to be measured that flows through an object to be measured inserted into a central part of the ring-like shape, a Hall element configured to be arranged in the voids of the magnetic core and output an electrical signal according to the magnetic flux, an inspection conductor configured to apply a predetermined magnetic flux generated by allowing a predetermined inspection current to flow therethrough to the Hall element, and an amplifier configured to amplify a Hall signal output from the Hall element (for example, refer to JP-A-2010-133737).
The current sensor device is capable of detecting a failure of the Hall element based on the Hall signal that is output from the Hall element and is amplified by the amplifier when the current to be measured does not flow through the object to be measured, and the inspection current is allowed to flow through the inspection conductor.